'Electronic nose' better than human sense of smell

Engineers have invented an “electronic nose” capable of detecting fruit odours more effectively than a human.

The device, which the researchers from Sweden and Spain claim is more sensitive than the human sense of smell, can currently only distinguish between the odorous compounds emitted by pears and apples.

The electronic nose has 32 sensors which gather real time data before the information is processed through classification algorithms. The results can be viewed on a 3D graph which distinguishes between the pear and apple scores.

"The fruit samples are placed in a pre-chamber into which an air flow is injected which reaches the tower with the sensors which are metal oxide semiconductors that detect odorous compounds such as methane or butane," explains José Pelegrí Sebastiá, UPV researcher at the Gandia campus and co-author of the paper.

The study, which is published in the Sensors and Actuators A journal, is the starting point for new research the team is already involved in to develop multisensory systems that increase the capacity to differentiate complex mixtures of volatile substances.

"One example would be the wine making sector where an electronic nose capable of distinguishing the quality or type of grape or recognising the vintage a wine belongs to would be very useful," says Pelegrí.

Other lines of research for the team focus on the field of biomedicine. Some studies have shown that trained dogs can detect cancerous tumours, such as lung cancer, by smelling a person's breath.

If this is true, and an electronic nose can detect which substances the animals recognise, then researchers may be able to diagnose the disease earlier and increase patients' survival rates.